Speed-changing device for bark-stripping machines.



W. WAERN.

SPEED CHANGING DEVICE FOR BARK STRIPPING MACHINES. APPLICATION FILED NOV.22, 1918.

1,301,199. Patented Apr. 22,1919.

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- rrnn STATES WILLIAM wnnnn, 0F STOOKHOLM, SWEDEN.

'srnnn-cnimemennvicn FOR BARK-STRIPPING MACHINES. V

matic speed changing device, whereby the working capacity of the machine is in creased according as the diameter of the trunk is decreased, which is desirable with regard to the fact that thin trunks can be moved without any disadvantage at the greater speed than thicker trunks. For the same purpose it has previously been proposed to 1ncrease the widthof the cut and at thesame time the speed by which the trunk is fed through themachine. An increase of the width of the out, however, has the disadvantage that crooked and irregu- 1m trunks are stripped ofl only partially,

.while by using a relatively narrow cut a satisfactory result can be obtained under all circumstances. 7 i

According to the present invention an increase of the working capacity of'the machine forthin trunks can beobtained without increase of the widthof .cut'by so devising the arrangementregulating the rate of feed of the trunk that the'peripheral velocity of the trunk is automatically increased according as the diameter of the trunk is decreased. In bark stripping machines of the kind in which the trunk is moved by means of a feedlroller-arranged at an angle relatively to the trunk, this isz'eifected in a simplema-nner by increasing the speed of rotation of the feed roller which is effected automatically by means of a changespeed gear operated by the adjustment of the feed roller to and from the trunk.

The invention will now be described with as reference to the accompanying drawing in Specification of Letters Patent.

Patented Apr. 22,1919.

Application filed November 22 1918. Serial No. 263,736.

which Figures 1 and 2 show a side view and a plan View respectively of a bark stripping machine provided with a-speed changing device according to the invention.

The rotatingcutter disk 1 is mounted in two bearings 2 and3 and is driven by means of apulley 4. The trunks are moved forward on rollers 5 between the cutter disk- 1 and the feed roller 6. The drawing shows a trunk 7 in working position. The roller 6, which is provided with spikes for engaging the trunk, is rotatably mounted in a stirrup 8, fixed to the'end of the shaft.9 which is slid'ably arranged in a sleeve 10and actuated by a spring 11 which tends to keep said shaft normally in the projecting position shown in the drawing. The sleeve 10 is mounted in guides 12 and at its lower side it is pro vided-with rack teeth 13 engaging a pinion 1 1 provided on the same shaft as a hand wheel 15, by means of which the feed roller 6 can be lifted from the trunk or forced against the same respectively.

The feed roller is driven by means of a bevel gear wheel 16 engaging a gear wheel 17 connected with the feed roller. The gear wheel 16'is provided on a spindle 18 which is 'journaled inthe shaft 9 and at its upper end provided with a gear wheel 19 engaging a pinion 20 with long teeth. Mounted on the same shaft as said gear wheel 20 is a bevel gear wheel 21 engaging .a gear wheel 22 on the shaft 23, which at its opposite end carries a pulley.21.' The movement is transmitted to the latter from the driving shaft 25 by means of: two conical pulleys 26 and 27, the shaft 28 and the pulley 29. The arrangement for changing the rate of feed is constructed in the following way. Fastened to an arm 30 projecting from the sleeve 10 ,is a rope 31 which is placed over the periphkeep the rope stretched. Between the disks 38 and 39 the rope 35 is fastened to one arm 41 of a belt shifter the other arm 42 of which is connected with the arm 41 by means of a toothed segment 43 so that both arms perform uniform movements. The guide pulley 36 is fastened toone end of an arm 44 and may be raised and lowered by means of a hand lever 45 which can be locked in different positions on an are 46.

During the operation of the machine the feed roller is forced against the trunk .by the weight of the slidable part 8, 9 and 10. By giving the feed roller the oblique position shown in the drawing the trunks will be fed forward lengthwise at the same time as they are given a movement of rotation.

It will appear from the above description that the speedxof rotation of the feed roller is increased when :the roller is moved a ainst the trunk, and decreased when the ro ler is moved away from the trunk the movement being transmitted to the disk 32 and the spiral disk 35 and through the latter and the rope 35 to the belt guide 41, 42 which effects aidisplacement of the belt 47 on the conical pulleys 26 and 27 whereby the speed is changed. Thus, thin trunks will obtain a greater peripheral velocity than thicker trunks. Consequently, the working capacity will be increased according as the diameter of the trunk decreases. To obtain a complete removal it is evidently also necessary that the pitchof the screw formed bark strip is maintained equal to the Width of the out. The pitch, however, varies with the speed of rotation of the trunk and in order to maintain the pitch constant it is therefore necessary to increase the speed of the longitudinalmovements .of the trunk on increasing the .speed of rotation. This is effected in known manner by turning the feed roller '6 on the shaft 9 so that the angle between the axle of the roller and the trunk is increased with increasing diameter of the trunk. In practice this regulation of the angular position of the feed roller is preferably effected automatically by controlling the movement of the roller correspondingly in a known manner.

The object of using a spiral disk 34 is to facilitate the varying of the degree of speed change for a certain displacement of the feed roller. For this purpose the spiral disk can be adjusted on the shaft 33 so that the rope 35 is Wound off or on more or less. If the rope 35 is wound over a large part of the curve on the spiral disk the movement transmitted to the belt shifter is diminished for the same displacement of the feed roller, and vice versa. The same purpose may, of course, also be attained by using a plurality of rope pulleys of different diameters instead of the spiral disk 34. By adjusting the guide pulley 36 the speed of rotation of the feed roller can, evidently, be changed for each adjusted position of the feed roller. This arrangement has particularly for its object to facilitate a rapid decrease of the rate of feed when crooked and irregular parts of the trunk are passing the feed roller.

It is obvious that a system of levers, shafts orthe like may beused instead of ropes for the transmission of the movements. Further, the feed roller need not necessarily be 'arranged slidably, but the shaft 9 may be arranged'swingably in a hangin position.

Having now described my invention and in what manner the same is to be performed I declare that what I claim. is

1.1m bark stripping machines provided with a feeding device adjustable with regard to trunks of different diameters and in which the trunk is rotated at the same time as it is fed forward lengthwise, the arrangement that the feeding deviceis connected with means for regulating the rate of feed in such a manner that the peripheral velocity of the trunk is automatically in- I creased according as the diameter .of the trunk decreases. Y

2. An arrangement according to claim. 1 applied to bark stripping machines provided with a feed roller arranged at anangle relatively to the trunk and by means of which the trunk is rotated at :the-sametimeas it is moved lengthwise, characterized by the feed roller being connected with .a speed changing device for regulating the rate of feed,

in such a mannerthat' the speed vofrotation of the feedroller is automatically increased with decreasing diameter of the trunk 3. An arrangement according to claims 1 and 2, characterized by a speed changingde vice being provided between the feed roller and the arrangement for regulating "the rate of feed of the trunk said speed changing device being adapted to regulate the change of speed corresponding to a certain displacement of the feed roller.

4. An arrangement according to claims 13, characterized by the change speed gear consisting of a rotatable spiral disk or the like over the spiral shaped periphery of which is placed a rope connected with the transmission device 10,31, 32, 35, 41, 42. p

5. An arrangement according to claims 1 and 2, characterized by a device for varying the rate of feed corresponding to certain 13, characterized by the arrangement for In testimony whereof I afiix my signature regulating the rate of feed of the trunk in presence of two Witnesses. being actuated by means of a rope or the like which is carried over a speed changing WILLIAM WAERN' 5 device and over an adjustable disk for the Witnesses:

purpose of effecting a, double regulation of JACOB BAGGE,

the rate of feed. CHARLES H. SAFELY.

Copies of this patent may be obtained tor he" cents each, by addressing the Commissioner of Patents,

' Washington, D. G." 

